An Overview of NoSQL and SQL Database

Is the SQL database outdated? Is a Relational Database Management System (RDBMS) no longer useful for business? Did NoSQL database replace SQL database? These are some of the frequently asked questions. Let us understand a clear difference between both databases and why we choose one over the other for our project. Here is the outline of the differences between SQL DB and NoSQL DB: <table style="font-size: 15px; border-collapse: separate;" cellspacing="10" width="100%"> <th style="width: 10%; border-bottom: none;"></th> <th style="background-color: #cad5d7; width: 45%; padding: 10px; border-bottom: none;">SQL DB</th> <th style="background-color: #cad5d7; width: 45%; border-bottom: none;">NoSQL DB</th> <tr> <td style="background-color: #cad5d7; padding: 10px; border-bottom: none;">Data Storage</td> <td style="background-color: #f1f5f6; padding: 10px; vertical-align: top; border-bottom: none;"> <ol style="text-align: left;"> <li>SQL DB is usually interpreted as a relationship database.</li> <li>Data is stored in Rows-and-Columns format in relational model. Rows contain information about one specific entry/entity whereas columns contain separate data points. Example: If we have a row about an employee, its columns will include EmpNo, EmpName, Salary, Dept, etc.</li> <li>Relationship databases usually have tables to maintain the entities and the relationships between them. It functions within strict time constraints and allows multiple data manipulations.</li> </ol> </td> <td style="background-color: #f1f5f6; padding: 10px; vertical-align: top; border-bottom: none;"> <ol style="text-align: left;"> <li>NoSQL is usually interpreted as Not Only SQL, it is recognized as a non-relationship database.</li> <li>NoSQL has a different data storage model. The main data is stored as a document, graph, key-value and columnar. The most popular record type of NoSQL is key-value stores.</li> <li>Being less constraint and having flexible a storage capacity, NoSQL offers more storage operational performance. NoSQL system is optimized to retrieve and append operations in its record storage architecture.</li> </ol> </td> </tr> <tr> <td style="background-color: #cad5d7; padding: 10px; border-bottom: none;">Schema and Flexibility</td> <td style="background-color: #f1f5f6; padding: 10px; border-bottom: none;">Schemas or record lengths are fixed, This means that the columns are decided and locked before data entry and each row contains data for each column. In order to amend the length, it is required to go offline and can also result in alteration of the whole database.</td> <td style="background-color: #f1f5f6; padding: 10px; border-bottom: none;">Schemas are dynamic. The Information can be added/modified on the fly, and each ‘row’ (or equivalent) doesn’t require data for each ‘column’.</td> </tr> <tr> <td style="background-color: #cad5d7; padding: 10px; border-bottom: none;">Scalability</td> <td style="background-color: #f1f5f6; padding: 10px; border-bottom: none;">Scaling is vertical, hence, more data storage may require bigger server, which can be very expensive. If you wish to scale an RDBMS across multiple servers, it will be a difficult and time-consuming process.</td> <td style="background-color: #f1f5f6; padding: 10px; border-bottom: none;">Scaling is horizontal, i.e., across servers. These multiple servers can be cheap commodity hardware or cloud instances, making it a lot more cost-effective than the vertical scaling.</td> </tr> <tr> <td style="background-color: #cad5d7; padding: 10px; border-bottom: none;">ACID Compliance (Atomicity, Consistency, Isolation, Durability)</td> <td style="background-color: #f1f5f6; padding: 10px; border-bottom: none;">The vast majority of relational databases are (Atomicity, Consistency, Isolation, and Durability) ACID compliant.</td> <td style="background-color: #f1f5f6; padding: 10px; border-bottom: none;">This varies with technology, but many NoSQL solutions do not comply by ACID for better performance and scalability.</td> </tr> </table>